Just two days ago, NBC Universal unveiled “Make Green Count” — a new “Green is Universal” Facebook application that encourages social action.

Here’s how it works: followers are asked to join their favorite NBCU brand and “pledge to change a part of their daily routine and positively impact the environment.” This can be anything from using cold water to wash clothes with Bravo or reusing a shopping bag with iVillage. Once pledging a commitment, users are rewarded with coupons for green purchases. It’s a win, win!

“We are thrilled to partner with Green is Universal on such a worthwhile, smart and creative program,” said Susan Hunt Stevens, Founder and CEO of Practically Green. “It’s one thing to ask people to wash their clothes in cold water, but giving consumers a tool that both shares their pledge behaviors and reduces the cost of a green lifestyle, adds incentive and provides a reward for acting more environmentally responsible.”

In just 2 shorts days, the application has received over 500,000 pledges, and the number keeps rising.